https://matteocampagna.com/en/registry/equipment/arrow-at-an-angle-more-drag Changes to this claim in Matteo Campagna's evidence registry: its status, its year-by-year history, revisions of the page. en-gb https://matteocampagna.com/en/registry/equipment/arrow-at-an-angle-more-dragThe threshold is around half a degree: as long as the arrow stays aligned with the airflow, the layer of air running along it stays laminar and the drag coefficient is about 1.5; as soon as it passes four to six tenths of a degree the layer turns turbulent and the coefficient rises to about 2.6, that is nearly double. The same jump has been measured in the tunnel with the angle imposed, where in 2017 three quarters of a degree is enough to take the coefficient from about 1.6 to about 3.1, and in free flight with a compressed-air launcher, including with an inertial sensor inside the shaft, where the deceleration goes from 0.65 to 0.30 G as the angle of attack falls below three tenths of a degree. In the turbulent regime the drag reaches 80 per cent of the arrow's weight, and two calculations, one from the same group and one from outside it but calibrated on its data, recover the same jump. There are two limits worth knowing. The first is that the jump only exists while the flow is still laminar: if it is already turbulent, drag stays nearly the same as the angle changes. The second comes from 2022 and cuts the angle down to size: between a tapered point at 0.46 and 0.51 degrees and a bulge point at 0.44, it was the point shape that decided the flow regime, not the angle. What remains is that nobody has measured how often an arrow shot by an archer actually crosses that threshold, or how far that crossing moves the point of impact over a real end.claim:inclinazione-resistenza:revision:2026-06-30:2Tue, 30 Jun 2026 08:00:00 GMT https://matteocampagna.com/en/registry/equipment/arrow-at-an-angle-more-drag#storiaA peer-reviewed journal article from the same group finds the threshold again with the angle imposed in the tunnel: at three quarters of a degree the air layer turns turbulent at a Reynolds number of about 11,000 and the drag coefficient goes from about 1.6 to about 3.1. In free flight, with the angle worked out by simulation, at 17,500 the coefficient stays around 1.5 if the largest angle is below 0.4 degrees and rises to about 2.7 above 0.6. The figures firm up, but they come from the same tunnel: the status stays reported.claim:inclinazione-resistenza:history_entry:2026-06-17:2017Wed, 17 Jun 2026 08:00:00 GMT https://matteocampagna.com/en/registry/equipment/arrow-at-an-angle-more-drag#storiaIn a water tunnel at very low speed, the flow stays attached at the point of four commercial arrows between minus six and plus six degrees of tilt and separates from nine degrees upwards. It is a regime far from that of flight, with Reynolds numbers below a thousand, it says nothing about drag and it appears in a questionable venue: the status does not change.claim:inclinazione-resistenza:history_entry:2026-06-17:2014Wed, 17 Jun 2026 08:00:00 GMT https://matteocampagna.com/en/registry/equipment/arrow-at-an-angle-more-dragclaim:inclinazione-resistenza:new_claim:2026-02-16:riportatoMon, 16 Feb 2026 08:00:00 GMT